1. Field of the Invention
The present invention relates to a device in which a base component is formed on a base plate and a functional film is additionally formed on the base component, a manufacturing method thereof, and an electronic instrument.
2. Related Art
Recently, a display device such as a liquid crystal display device has been extensively used for an electronic instrument such as a cellular phone and a portable personal computer.
Conventionally, as a color filter substrate used for such display device, a substrate having a structure shown in FIG. 11, for example, has been known. In FIG. 11, the sign “201” denotes a base plate, and on this base plate 201, respective color pixels 202R, 202G, and 202B of R (red), G (green), and B (blue), which constitute a color filter, are formed in a predetermined arrangement such as a striped arrangement, a mosaic arrangement, and a delta arrangement, and an overcoating film 203 is additionally formed thereon.
Here, the formation of the overcoating film 203 (over coating layer) on the color pixels 202R, 202G, 202B is to allow the overcoating film 203 to perform the following functions.
The first function is to prevent disconnection of electrodes formed on a surface of the color filter substrate by planarizing the surface of the color filter substrate with the formation of the overcoating film 203.
The second function is to enable the lamellation and low resistance of the electrodes by preventing disconnection, thereby improving contrast ratios between pixels.
The third function is to prevent the pixels (color pixels 202R, 202G, 202B) within the color filter substrate from being damaged and to protect them in process steps subsequently performed after forming the overcoating film 203.
The fourth function is, in the case where the color filter substrate is used for a liquid crystal display device, to prevent impurities from diffusing from the color filter substrate to the liquid crystal after the liquid crystal is enclosed in the cell gap.
Conventionally, after forming the plural color pixels 202R, 202G, 202B of R (red), G (green), B (blue), or C (cyan), M (magenta), Y (yellow), etc. on a predetermined area partitioned by a black matrix 204 on the base plate 201, the overcoating film 203 having above mentioned functions has been formed thereon, i.e., on an entire surface of the black matrix 204 and the color pixels 202R, 202G, 202B, by coating liquid transparent resin such as resist in uniform thickness by the spin coating technique etc.
Further, as a forming method of the color pixels 202R, 202G, 202B, which precedes the step of forming the overcoating layer 203, a method for patterning color pixel materials in the form of films of respective colors by using the photolithography technique has been adopted.
However, in the case where the patterning is performed by using the photolithography technique to form respective color pixels, since the steps are complicated and the respective color pixel materials, photo resist, etc. are used in large quantities, the problem of increased costs occurs.
Therefore, in order to solve this problem, a method for discharging filter material (color pixel material) etc. in the form of dots by the droplet discharging technique (ink jet technique) to arrange and form a component such as color pixels in a dotted form is proposed.
More specifically, as shown in FIG. 12(a), at first, bank-shaped partition members 6 having a predetermined height are formed on a base plate 2. These partition members 6 are formed from resin material etc. having liquid repellency to liquid filter materials 5 (see FIG. 12(b)) discharged by the droplet discharging technique. Alternately, after forming the member, a liquid-repellent film is formed on a surface thereof for performing liquid repellency. Then, since the partition members 6 have liquid repellency to the filter materials 5, the filter materials 5 adjacent to each other are prevented from being mixed because the partition members 6 are interposed between them, and each of them will independently form a color pixel as shown in FIG. 12(b).
As described above, a color filter constituted by the color pixels 3 (3R, 3G, 3B) can be formed by the droplet discharging technique, as shown in FIG. 12(c). In addition, a color filter substrate can be fabricated by forming an overcoating film 4 on the color pixel 3 (3R, 3G, 3B), as described above and shown in FIG. 12(d).
However, by the method as shown in FIG. 12, since the partition members 6 have liquid repellency, they also perform liquid repellency to the liquid material of the overcoating film 4 coated thereon, as a result, coating irregularities of the liquid material occur on the surface of the partition members 6. Then, since irregularities in film thickness occurs in the overcoating film 4, the above-described four functions of the overcoating film can not sufficiently be performed, and therefore, in a device such as a liquid crystal display device, an inconvenience such as degradation of display quality will occur.
In addition, other than the overcoating film (over coating layer), with respect to a film and a layer provided on various base components formed on a base plate such as a planarizing film, an interlayer insulative film, and an alignment film used in a liquid crystal display device, it is also desirable that the film (layer) is planarized and uniform for the purpose of performing its required functions without being affected by irregularities due to base components.
The present invention is achieved in light of the above, and an object thereof is to planarize a functional film formed on a base component and uniform its thickness, thereby providing a device in which a function of the functional film is intended to be improved, a manufacturing method thereof, and an electronic instrument.